In the use of heat pumps of space heating, e.g. the heating of a dwelling, a heat exchanger is provided in contact with atmospheric air so that heat is abstracted from the air by the heat pump and is distributed in the dwelling unit.
This heat exchanger can have surfaces in contact with wind-blown air, the natural air currents (i.e. the wind) displacing the air in contact with the heat exchange surfaces.
The heat pump is a thermodynamic machine operating with a fluid (heat carrier) circulation between a thermal reservoir at ambient temperature and a thermal sink at a higher temperature. In the case of building heating with such a pump, the thermal reservoir is the ambient atmosphere while the sink is the air or space within the building.
To circulate the heat carrier, electrical energy is used and the amount of heating in the dwelling is greater than the equivalent amount of electrical energy as a result of the abstraction of heat from the exterior and its transfer by the heat-carrying fluid to the interior.
While heat reservoirs of the type utilized in the past have included bodies of water, ground water and even the earth, efforts have also been made to exploit the sensible heat of atmospheric air for this purpose.
The present invention is concerned primarily with abstracting heat, in a heat-pump system, from this atmospheric air.
Conventional heat exchangers or heat transfer devices for the heating of a heat transfer fluid from the sensible heat atmospheric air generally comprise plate-like elements which are built into a roof structure and hence are contacted on one side only by air which may be blown thereover. The air is passed over these surfaces by wind energy and the surfaces can be connected thermodynamically in parallel although in some cases a tandem or series connection is provided.
Experience has shown that heat exchange surfaces of this type are unsatisfactory in many cases, that large areas are required which may not be available for built-in roof heat exchangers, and that connection of numerous heat exchanger surfaces spread throughout a roof structure can be expensive and difficult. These surfaces, moreover, become inefficient at low wind speeds.